Hydraulic engine



.fne-25, 1935. E. M. EYNARD Y m37 HYDRAULIC ENGINE 1 Filed March 24,1934 3 sheets-sheet 1 June25f1935r mv-NARU 2,006,231;

HYDRAULIC ENGINE Filed March 24, 1954 -r 3 Sheets-Sheet 2 June 25, 1935.E. M. EYNARD HYDRAULIC ENGINE Filed March 24, 1954 3 Sheets-Sheet 3Patented June V25,y 1935 UNITED STATES PATENT OFFICE v 2,006,237v onYnaAUuc rincaro?.k l l r` Elysee Marius Eynard, Boulogne-Billancourt,"

France Aaaucafmn'LMahf2a 1934, seriarNo. 717,252 FranceApril 7,1933 H fs claims. (o1. 121-120) 'lh present invention is concerned with dervices. for transmitting'hydraulic power, of the kind in which .theprimemover discharges a iluid which is introduced, at constantydelivery, intoa hydraulic motor controlling the member toV be driven and Whose.delivery, per; revolution may bevaried according to the load, wherebythespeed of the hydraulic motor is varied and it is possible.

to strike a balance between theload and the driving torque.

The invention ismore p'articularly concerned with a distributor for.suchatype of 'hydraulic motor. vSuch distributor is constituted by aslide valve the position of which. controls the delivery perrevolutionjof the hydraulic 'motor and,.con-` sequently,. the speedofthe driven member, one ofthe faces of said slide. .valvebeing subjectedto the .action of a fluidV dischargedby the prime mover and brought toa] substantially constant predetermined 'pressure by a pressure controldevice,` while ,its other face'is subjected to .the same pressurereducedgfhoweverg'by theloss of head resulting from Vthe entry of thefluid into the motor and which depends onthe load. on the motor, sothat'the position of the slide valve and,

likewisedepends on the load. i o

Othercharacteristics and -features of the invention will become apparentfrom the.. ensuing 30 panying drawings whereinzf- I Fig. l1 is asectional elevation of rstlexnbodi? ment of a 'hydraulic' motoraccording 'to they invention. 4

Figs. la and 1b are'views of theycontrol cams Fig. 2 isa cross sectiononthe'line *IIvIoI of Figli.'` Fig 3v is a'y detail view of theautomatic dis-5 .trlbutor. 40

Vapplication of the invention. y y

Fig. 5 is a sectionv along the-line V-V'of Fig. 4.

rods Bare-3a, 31a-3b, 3c-3c, connected in pairs. bythe braces da,412,40. Qn saidrbraces act the` pistons ofy the motoriwhich, intheexample illustrated, are arranged .in groups of .threefpistons'disposedin Vstar formation. The rst of thefse 6c and so on. The pistonssuch as 5a, 6a, 1a',

consequently, the speed of rotationof said motor,

description taken with reference to.y the accom- Fig. 4 is @longitudinalsection or a" modified.'

' Fig. 6 is a sectional 'elevation' of another-appligroups is designated5a, 5b, 5e; the second 6a, 6b,

l etc., may act onthe brace 4a; the pistons such as 5b, 6b, 1b, etc., onthe brace IIb;r thenpistons 6c, 6c, 1c, etc.,l on the brace 4c. It -willbe observed that this arrangement is only given'by way of e`x`- A ampleand that each set of pistons-might comprise 5 any number of pistonsother than three; anequal" numberl of braces 4' would then be 'provided.Moreover, there may be any number-of sets'of pistons disposed instarformation.v Finally, the pistons 5 of the first set have,beenillustrated 10 as 'being' of greater A diameterr than that of vthepistons of the other sets,i but this designis cptional for the diametermay be the same for all pistons or may decrease from set tor set.,`

'This hydraulic motor receives fluid dischargedv 15- by anyappropriatemeanasuch as a pump, ynot illustrated,l driven. by the motorwhose power it is desired to transmit tothe crank vshaft I.

The distributing mechanism according' to the invention comprises for`each longitudinal group oi'opistons such as 5a, 6a, 'la ,v a! slidevalve I I vin the form of a diierential piston, whose large piston I2reciprocates in a cylinder I3 extending the length of the correspondinglongitudinal row of pistons, while the .smallpiston' I Ireciprocates "25in a cylinder I 5 in direct communication with the fluid' inlet pipeVle," j 1 In theductI'I which connects'the pipe I6 with the cylinder I3,is inserted a pressure-control device, the purpose of which isto bringthe uid to the desired pressure andl 'which comprises a piston 20 on'which" acts a'calibrated spring 20a or any other mechanical, hydraulicor pneumatic restoring means. To reach'the vcylinder y I3, thedischarged uid has to.' overcome the re- 35 sistance of vthe spring 20a,whereby said fluid is .brought tothe' desiredpressure. .Intlie duct I1vis likewise mounted an inlet valve I8, controlled by a distributing camI9set on the shalt Said cam is common to the three inlet valves I8. The40 cylinder vI3 communicates with the cylinders or'. the correspondingpistons through passages. ifa, 6'a,jetc. The cylinder I3v likewisecommunicates; with 'an outlet vpassage 2Ia in which is .mounted a. valve2|. 'actuated by `asecond cam-.22. The cylinder I3 nally. communicatesat-itsyleft en with a second outlet passage I8a. It will be observedthat the slide valve 'I I is sub-A jected, on the fone liand,.inthecylinder I5 to the. 50 action of thev fluid arriving through the pipeI8 i and put under pressure by the pressure control device 20 and, onthe' other hand, in the cylinder I3 to the action 'of the'lsame pressurereduced however, by' the loss* of head'due to the fact that 55" saidcylinder I3 communicates ,with one or more ofthe cylinders of thepistons a, la, etc. Y

Y The apparatus operates in the following mannler: On starting,- theslide valve II is in its right end position (position of Fig. 1) inwhich theV cylinder I3 communicates solely with the cylinder of thepiston 5a. Naturally, the cylinders of f rthe pistons 5b 5c ofthe sameset communicate with the `corresponding distribution cylinders A I3.

Consequently, the pressure fluid acts Von the first" set of pistons 5a,5b, 5c which rotate Ythe crank shaft I through the medium of the braces4 and connecting rods 3. If the load on the crank shaft is such that theloss of pressure head in the cylin-` der I3, duev to the now of pressurefluid Ain the cylinders ofthe rlrst set of pistons', 5a, Ib, 5c, ex-.

actly compensates the dinerence of the surface area ofthe pistons I2 andI4 of the slide valve II,

said slide valve will remain stationary and only the first set ofpistonswill operate rotating the *y crank shaft directly at the highestpossible speed.'

*snouldtne load on` the 'crank shaft I increase., its speed and thespeedoi' displacement of the. pistons 5 fall off, andthe loss ofpressure head` in-each of lthe cylinders1ll decreases; On this account.'the pressure onthe distributor piston I2 increases andthe s lidefvaive II `moves to the left thus uncovering the'passageA I'a, whereby thesecond set of pistonsfla is brought into circuit,... lILcOnsequentthereon, equilibrium 'is established between the pressure on the pistonIl and that on the'piston I2,`the'slidevalve II will come to rest inthis position in which 'the two first sets of pis.-l tonsi and ioperateto, drive the shaft I., ata slightly lower speed than before;Should the loss of pressure l'ieadV still decrease due to the in-Vcrease ofV load, the 'slidefvalvel II uncoversl other passages such as1a,8'a,etc., bringing a greater ynumber of pistons intocircuit, wherebythe speed of the crankshaft I is correspondingly reduced.

Y suchfspeed beingthus proportional to the load LAes Vmine'according'to'their position, which depends on theload, the number of Y Y Y Sets ofpistons which are brought intocircuit.` i'

YThe automatic distributing 'mechanism' accuraing to the invention maybefappiied toother 'than Vpiston motors. A n Y Thus; inlFigs. ViV and-5`,V such mechanism has been shown 'applied to a hydraulic motorwherein each set of. pistons is replacedby a set of receiving gears 23a,23h, 22e.' etc., on which the iluid acts'torotate them. j K

In the example illustrated, a distributor Il is provided'- for forwarddrive and a distributorl IIaV for reverse` drive,r andthe vpumphas beenillus trated at. Said pump dischargesthewuid through Ythe-duct Il. Saidfluid acts'on the pressurecontrol device 2li which, in this case,lik'e.Y

" wise Vserves to reverse the drive. In the figure, it

is represented-in the position for forward'drive, for, when it isdisplaced under the action 0I the iluid. :it admitsY a iluid into thecylinder Il but prevents access of the fluid (through the medium of itsskirt I2)4 to thecylinder Ila, whichfor.

Y forward drivezserves for theexrhaust into anexhaust Areceiver formedby the chamber provided within Ythe central portion of the frame. yOn,the

other hand.V ifthe;V pressure control device III bcl Vcentrics 21 and28.

9,000,937 Y, rotated through' 180, it is the cylinder Ila which receivesthe pressure fluid and theapparatus then operates in reverse.

The mechanism according to the invention may likewise be applied tomotors of the type shown in Figs. 6 and 7, that is to say, whichcomprise a circular series of cylinders. set on the driving shaft I andin which reciprocate pistons 25 whose heads are connected to aneccentric memberl 26 whose eccentricity with ,respect to the axis of theshaft I may be varied by means of ec- Such eccentricity may be varied byimparting a relative angular displacement to the eccentrica 21 and 2B,for example, by means of the toothed pinions 29, 29a and the shaft 3o.The pinion 29a is fixed on theshaft .3l and controls the eccentric 28through the instrumentality of the toothed sector 33a which is securedto the latter; the pinion 29 is. controlled by the pinion 28a and itselfcontrols the sector 33 `secured to the eccentric 21. Such relativeVangular displacement "alters the throw ofthe Vouter eccentric 21 and[hence of the member 2l which is mountedL on saidrec'centricV 21 on ballf bearings al. 'rnisais a known 'typej of hydraulic motor. vWhen' thevvmechanism according tothe invention is applied to said motor, it isonly hecessaryto providebetween the slidevalvev I I and the shaftv l0, asuitable n'iecohanieal connection through the medium v`of which theslide valve. II-

as it moves controls the relative angular displacementoi the eccentrica21 and 28', and, consef quently, theposition'ofthemember' 20. On the'cylinders 2l and, 'consequentlmythe at"i which the driven shaft Iisrotated.f The meiy `chanical connection may be constituted by 'a2 plainrod $1 which exltiids kthe valve ,Il and which is connected infanyvsuitable manner It'ofa'- lever`82'set on the shaft 20. l

`It is evident,omoreover,"that the invention might be applied to othertypes of hydraulic motors, the

essential characteristic of the invention residing ina slide valve whichautomatically takes upa position yof equilibrium in which the vmotor".tof which it is applied rotatesatga 'speed correspond' ing to the loadonit,

1.91am!! j 5 `1./ Incombination with' a motor adapted tobe driven byhydraulic power, adistributor for con-` trolling the Supply of pressurefluid to said motor. f'

comprising, in combination, a slidel valvev including two coupleddifferential pistonsz adaptedto movein corresponding cylinders,interconnected fluid 'inlets fofadiitting Vtlid to the v'oppositev endsof said cylinders, the larger' of Asaid cylinders communicating withsaid motor fnsuch" wise that while the smaller piston 'is subjected totheV full pressure of said iiuid the larger piston is sub# jecteu te'and pressure reduced by the lass oriiead,

determined bye-the load on saidv motor, and pres-- sure control meansmounted in theuiddnlet to said larger cylinder for` preventing admissionof lfluid into sainz-larger cylindery until the pressure of the tluidhas reached a predetermined value.

.2. Apparatus according ytolclaixn l. wherein the pressure controlmeans* Ycomprise ya piston' valve anda` spring tending to hold saidpiston valve in position to cut oflthe admission of iluid exerted bysaid fluidon said pistonvalve. -f

3. Apparatus according to.claim-1,'in-corrilrinl'afl vto the largerofsaid cylinders against Vthe thrust cular series of cylinders set onsaid drive shaft, pistons adapted to reciprocate in said cylinders, twosuperposed eccentric membersl mounted on said drive shaft and capable ofrelative angular displacement, an outer eccentric member surrounding thesaid two eccentric members and to which the heads of said pistons areconnected,

whereby the relative angular displacement of said two eccentric membersalters the throw of said outer eccentric member, and a linkage mechanismfor coupling said two superposed eccentricmembers to vsaid slide valveto be controlled 5 by the displacementl ot the latter.

-ELYSEE MARIUS EYNARD.

